That doesn't indict communities and their social and emotional importance.
If anything, it proves GP's point. The coexistence of dysfunctional communities and no-community within a culture actually seems pretty congruent. It just points to both of these being caused by dysfunction in the culture.
Nearly every community is healthy and wonderful if they're like you in the ways you care about and you have membership. Nearly every community is dysfunctional if it's different in the ways you care about and you lack membership.
Most people I know seem to define "community" based purely on geography and some localist shared identity. I, personally, am not a fan of this. I find it too arbitrary and and far too likely to attempt to co-opt me into supporting things directly against understanding of my interests. I fully understand why some other people value such things.
And yes, it's possible that I'm just an asshole that nobody ever wants in their community.
Of course, all of this only applies if you're sufficiently like them to be judged worthy of membership.
Well, of course. A group who accepts anyone and everyone loses its identity. The real problem is that people don't have freedom of movement: that is, the ability to seek out and join a group that they truly fit in with.